First of all, I'm just average user with no programming background. I know how to copy-paste commands in terminal but dont know what they actually do.

Anyway, so I downloaded the latest upgrade last week then came by this forum to install nvidia driver from this thread:viewtopic.php?f=191&t=82424

My card was geforce 9300M, it is an AiO PC from HP. Quite old so I dont remember the model. LMDE was installed for a couple of years, and when I check the graphic card driver, it was not the nvidia one (so one of the generic, i think). Anyway, I decided to install by using this command: